The analysis surveyed 1,000 participants in the Marathon, and assessed their spending in categories such as hotel, travel, entertainment and retail.

The 2010 race drew 45,350 participants, 2 million spectators, and a television reach of 315 million worldwide.

Runners alone spent $1,800 over the course of the weekend.

If you average four guests per runner, you get $326+ million.

The race also yields direct tax revenues of between $10.8 to $11.2 million.

And it provides $24.3 million to NYC charities.

But with airports having shut down this week, the $340 million figure is likely already compromised.

Meanwhile, Sports Marketing Frontiers estimatesING paid more than $4 million to sponsor the marathon.

David Carter, executive director of the University of Southern California's Sports Business Institute, told us there was no way of knowing what kind of penalty the city would incur to ING if it canceled.

He added that too much time would have elapsed for any force majeure clause in the sponsorship deal to have been invoked.

"If the storm rolled through today, many would believe there was no way to run it," he said. "Whereas some now believe the run could go off, that there is maybe sufficient time to make an informed decision, and that it was not part of act of god."

There's also a third party with millions at stake.

The New York Road Runner's club is the official organizer of the race. Its annual revenue is approximately $55 million, of which the marathon is the biggest revenue driver, according to Fox News.